Neotropical mammal responses to megafires in the Brazilian Pantanal.

The increasing frequency and severity of human-caused fires likely have deleterious effects on species distribution and persistence. In 2020, megafires in the Brazilian Pantanal burned 43% of the biome's unburned area and resulted in mass mortality of wildlife. We investigated changes in habitat use or occupancy for an assemblage of eight mammal species in Serra do Amolar, Brazil, following the 2020 fires using a pre- and post-fire camera trap dataset. Additionally, we estimated the density for two naturally marked species, jaguars Panthera onca and ocelots Leopardus pardalis. Of the eight species, six (ocelots, collared peccaries Dicotyles tajacu, giant armadillos Priodontes maximus, Azara's agouti Dasyprocta azarae, red brocket deer Mazama americana, and tapirs Tapirus terrestris) had declining occupancy following fires, and one had stable habitat use (pumas Puma concolor). Giant armadillo experienced the most precipitous decline in occupancy from 0.431 ± 0.171 to 0.077 ± 0.044 after the fires. Jaguars were the only species with increasing habitat use, from 0.393 ± 0.127 to 0.753 ± 0.085. Jaguar density remained stable across years (2.8 ± 1.3, 3.7 ± 1.3, 2.6 ± 0.85/100 km2), while ocelot density increased from 13.9 ± 3.2 to 16.1 ± 5.2/100 km2. However, the low number of both jaguars and ocelots recaptured after the fire period suggests that immigration may have sustained the population. Our results indicate that the megafires will have significant consequences for species occupancy and fitness in fire-affected areas. The scale of megafires may inhibit successful recolonization, thus wider studies are needed to investigate population trends.

A crescente frequência e gravidade dos incêndios causados pelo homem provavelmente terão efeitos deletérios na distribuição e persistência das espécies. Em 2020, mega incêndios no Pantanal brasileiro queimaram 43% do bioma e resultaram na mortalidade em massa da vida selvagem. Nós investigamos mudanças no uso ou ocupação do habitat para uma comunidade de oito espécies de mamíferos na Serra do Amolar, Brasil, após os incêndios de 2020, usando um conjunto de dados de armadilhas fotográficas instaladas no período pré e pós­fogo. Além disso, estimamos a densidade de duas espécies naturalmente marcadas, a onça­pintada Panthera onca e a jaguatirica Leopardus pardalis. Das oito espécies, seis (a jaguatirica, o cateto Dicotyles tajacu, o tatu­canastra Priodontes maximus, a cutia Dasyprocta azarae, o veado mateiro Mazama americana e a anta Tapirus terrestris) tiveram ocupação reduzida após os incêndios, e uma teve uso de habitat estável (a onça­parda, Puma concolor). O tatu­canastra apresentou o declínio mais acentuado na ocupação após os incêndios de 0,431 ± 0,171 para 0,077 ± 0,044. A onça­pintada foi a única espécie com uso crescente de habitat, de 0,393 ± 0,127 para 0,753 ± 0,085. A densidade da onça­pintada permaneceu estável ao longo dos anos (2,8 ± 1,3, 3,7 ± 1,3, 2,6 ± 0,85/100 km2), enquanto a densidade da jaguatirica aumentou de 13,9 ± 3,2 para 16,1 ± 5,2/100 km2. No entanto, o baixo número de onças­pintadas e jaguatiricas recapturadas após o período do fogo sugere que a imigração pode ter sustentado as populações. Nossos resultados indicam que os mega incêndios terão consequências significativas para a ocupação e resiliência das espécies nas áreas afetadas pelo fogo. A escala dos mega incêndios pode inibir uma recolonização bem­sucedida, pelo que são necessários estudos mais amplos para investigar as tendências populacionais.

The adoption of climate-smart agriculture to address wildfires in the Maya Golden Landscape of Belize: Smallholder farmers' perceptions.

Ecosystems around the globe are enduring wildfires with greater frequency, intensity, and severity and this trend is projected to continue as a result of climate change. Climate-smart agriculture (CSA) has been proposed as a strategy to prevent wildfires and mitigate climate change impacts; however, it remains poorly understood as a strategy to prevent wildfires. Therefore, the authors propose a multimethod approach that combines mapping of wildfire susceptibility and social surveys to identify priority areas, main factors influencing the adoption of CSA practices, barriers to their implementation, and the best CSA practices that can be implemented to mitigate wildfires in Belize's Maya Golden Landscape (MGL). Farmers ranked slash and mulch, crop diversification, and agroforestry as the main CSA practices that can be implemented to address wildfires caused by agriculture in the MGL. In order to reduce wildfire risk, these practices should, be implemented in agricultural areas near wildlands with high wildfire susceptibility and during the fire season (February-May), in the case of slash and mulch. However, socio-demographic and economic characteristics, together with a lack of training and extension services support, inadequate consultation by agencies, and limited financial resources, hinder the broader adoption of CSA practices in the MGL. Our research produced actionable and valuable information that can be used to design policies and programs to mitigate the impacts of climate change and wildfire risk in the MGL. This approach can also be used in other regions where wildfires are caused by agricultural practices to identify priority areas, barriers and suitable CSA practices that can be implemented to mitigate wildfires.

Alterações climáticas e sua repercussão sobre a saúde humana em países da América do Sul / Climate change and its impact on human health in South America

Nas últimas duas décadas as mudanças climáticas têm se intensificado, causado danos ao meio ambiente e aos indivíduos que nele habitam. Várias ações do ser humano têm contribuído para que cada vez mais essas mudanças climáticas sejam mais presentes e intensas. O aumento das desigualdades e vulnerabilidades sociais, o desmatamento, os incêndios florestais voluntários, a degradação do solo e a poluição ambiental aliados à variabilidade climática global da temperatura da água do mar podem potencialmente levar a eventos climáticos extremos, potencializando os efeitos negativos sobre a saúde. Neste trabalho é apresentado um resumo do relatório do Lancet Countdown South America, fruto da colaboração acadêmica multidisciplinar de instituições de ensino e agências sul-americanas de saúde de 12 países (Argentina, Bolívia, Brasil, Colômbia, Chile, Equador, Guiana, Paraguai, Peru, Uruguai, Venezuela e Suriname) publicado por Hartinger e cols. (2023). Este estudo é uma alerta, pois nele são publicados os resultados do levantamento sobre mudanças climáticas e seus efeitos sobre a saúde humana no continente sul-americano. Conhecê-las é o primeiro passo para que políticas de saúde pública sejam instituídas, e, preferencialmente, de modo preventivo.

Climate change has intensified in the last two decades, damaging the environment and those who inhabit it. Human activity has increased the prevalence and intensity of these changes. Increased social inequality and vulnerability, deforestation, intentional forest fires, soil degradation, and environmental pollution, when associated with sea temperature variability, can lead to extreme weather events, increasing negative health effects. This report summarizes Lancet Countdown South America (Hartinger et al. 2023), the result of multidisciplinary collaboration between education institutions and South American health agencies from 12 countries: Argentina, Bolivia, Brazil, Colombia, Chile, Ecuador, Guyana, Paraguay, Peru, Uruguay, Venezuela and Suriname. This should be considered a wake-up call because it contains the results of a climate change survey and its effects on human health in South America. Knowing these effects is the first step toward appropriate, preferably preventive, public health policies.

Effects of fire on soil organic matter in northern Amazonian forest fragments / Efeitos do fogo sobre a matéria orgânica do solo em fragmentos de floresta no norte da Amazônia

Forest fires incorporate pyrogenic organic matter into the soil, affecting the characteristics of soil organic matter (SOM) due to its high aromaticity, increasing its renewal time. However, the factors that control the concentration of pyrogenic organic matter and its chemical composition and structure are still little known. Forest fragments dispersed in a savanna matrix of the northern Brazilian Amazon are frequently impacted by fires, which can affect the composition of SOM within the fragments. The aim of this study was to analyse the chemical composition of SOM in the border and interior of six forest fragments in the Roraima savanna, in the northern Brazilian Amazon. Soil samples were collected at 10-cm intervals up to 1 m in depth at the border and in the interior of each fragment. Soil organic material concentration was determined with 10% HF solution and its elemental composition, thermogravimetric index, and 13C CPMAS NMR spectroscopic analysis were determined. There was no significant difference in the aromaticity index between border and interior. The concentration of alkyl C structures between border (22 to 25%) and interior (19 to 29%) indicated the occurrence of medium-intensity fires in the study area. The thermogravimetric analysis showed no significant difference in the thermal stability of SOM between border and interior. Our results showed no pronounced difference in SOM quality up to 1 m depth between the border and the interior of the evaluated forest fragments, indicating that this compartment is stable throughout the fragments.(AU)

Incêndios florestais incorporam matéria orgânica pirogênica ao solo, afetando as características da matéria orgânica do solo (MOS), devido a sua alta aromaticidade. Porém, os fatores que controlam a composição química e a estrutura da matéria orgânica pirogência ainda são pouco conhecidos. Fragmentos florestais dispersos em uma matriz de savana na Amazônia setentrional brasileira são freqüentemente impactados por incêndios, que podem afetar a composição da MOS nos fragmentos. O objetivo deste estudo foi analisar a composição química da MOS na borda e no interior de seis fragmentos florestais situados na savana de Roraima, norte da Amazônia brasileira. Amostras de solo foram coletadas em intervalos de 10 cm até 1 m de profundidade na borda e no interior de cada fragmento. A concentração da MOS foi determinada com solução de HF a 10% e sua composição elementar, índice termogravimétrico e análise espectroscópica de 13C CPMAS RMN foram determinados. Não houve diferença significativa no índice de aromaticidade entre borda e interior. A concentração de estruturas alquil C entre a borda (22 a 25%) e o interior (19 a 29%) indicou a ocorrência de incêndios de média intensidade na área de estudo. A análise termogravimétrica não mostrou diferença significativa na estabilidade térmica da matéria orgânica do solo entre a borda e o interior. Nossos resultados não mostraram diferença pronunciada na qualidade da MOS até 1 m de profundidade entre a borda e o interior dos fragmentos florestais avaliados, indicando que este compartimento é estável ao longo dos fragmentos.(AU)

Chispas, cambio climático y actividades humanas. El triángulo de fuego que está quemando nuestros ecosistemas / Sparks, climate change and human activities. The fire triangle that is burning our ecosystems

El fuego ha ocurrido naturalmente en los ecosistemas, volviéndose incluso esencial para la evolución de la biodiversidad en algunos de ellos. Pero, así como hay ecosistemas que literalmente surgen de las cenizas, existen otros que, por el contrario, se ven gravemente afectados por las conflagraciones. La intervención humana, sumada a las altas temperaturas derivadas del cambio climático, están creando el cóctel perfecto para que los incendios forestales sean cada vez más voraces. ¿Cuál es la chispa que inició todo?

Fire has occurred naturally in ecosystems, even becoming essential for the evolution of biodiversity in some of them. But, just as there are ecosystems that literally rise from the ashes, there are others that, on the contrary, are seriously affected by the conflagrations. Human intervention, added to the high temperatures derived from climate change, are creating the perfect cocktail for forest fires to become increasingly voracious. What is the spark that started it all?

Modeling susceptibility to forest fires in the Central Corridor of the Atlantic Forest using the frequency ratio method.

Fire is one of the main disturbances of tropical forests. Understanding the spatial and temporal dynamics of forest fires is of fundamental importance for the conservation of tropical forests. We used a frequency ratio model to identify those areas most susceptible to forest fires in the Central Corridor of the Atlantic Forest, from 2001 to 2019. We used data from the burned area of MODIS MCD64A1 to create the dependent variable grouped as climatic, topographic and human and landscape variables. The receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to assess the model's performance. Land use and relief orientation were the most and least important variables in the model, respectively. The model showed good AUC values, ranging from 0.72 to 0.96, with an average of 0.81 for the study period. The average distribution of susceptibility classes was low (19.62 %), medium (24.45 %) and high (20.55 %). The northwestern region of the CAFC was the one that presented the greatest susceptibility to the occurrence of forest fires. The frequency ratio proved to be a good model for mapping areas susceptible to forest fires in an area of the Atlantic Forest.

Tracking the impacts of El Niño drought and fire in human-modified Amazonian forests.

With humanity facing an unprecedented climate crisis, the conservation of tropical forests has never been so important - their vast terrestrial carbon stocks can be turned into emissions by climatic and human disturbances. However, the duration of these effects is poorly understood, and it is unclear whether impacts are amplified in forests with a history of previous human disturbance. Here, we focus on the Amazonian epicenter of the 2015-16 El Niño, a region that encompasses 1.2% of the Brazilian Amazon. We quantify, at high temporal resolution, the impacts of an extreme El Niño (EN) drought and extensive forest fires on plant mortality and carbon loss in undisturbed and human-modified forests. Mortality remained higher than pre-El Niño levels for 36 mo in EN-drought-affected forests and for 30 mo in EN-fire-affected forests. In EN-fire-affected forests, human disturbance significantly increased plant mortality. Our investigation of the ecological and physiological predictors of tree mortality showed that trees with lower wood density, bark thickness and leaf nitrogen content, as well as those that experienced greater fire intensity, were more vulnerable. Across the region, the 2015-16 El Niño led to the death of an estimated 2.5 ± 0.3 billion stems, resulting in emissions of 495 ± 94 Tg CO2 Three years after the El Niño, plant growth and recruitment had offset only 37% of emissions. Our results show that limiting forest disturbance will not only help maintain carbon stocks, but will also maximize the resistance of Amazonian forests if fires do occur.

Environmental risk in Northeast Brazil: estimation of burning areas in Coreaú River Basin, Ceará, Brazil.

This work aims to estimate the burned areas in the hydrographic basin of the Coreaú River, State of Ceará, north of Northeast Brazil, which has an area of 10,633.67 km2, through the NOAA/AVHRR satellite, between the years from 2010 and 2017. The data were acquired at the base of INPE, where they were tabulated and generated a vector file of points. A density map of the fire sources was elaborated, from which the burned areas were estimated in the watershed studied over the defined period of years. There were 1786 fire outbreaks, totaling an estimated accumulated area of 1187.66 km2 of fires, which corresponds to 11.17% of the entire length of the hydrographic basin. The municipality of Mucambo presented a ratio of 40% of its territory comprised by the mapped fires. In relation to the conservation units, they mapped 795 hot spots in their perimeters.

The Unintended Impact of Colombia's Covid-19 Lockdown on Forest Fires.

The covid-19 pandemic led to rapid and large-scale government intervention in economies and societies. A common policy response to covid-19 outbreaks has been the lockdown or quarantine. Designed to slow the spread of the disease, lockdowns have unintended consequences for the environment. This article examines the impact of Colombia's lockdown on forest fires, motivated by satellite data showing a particularly large upsurge of fires at around the time of lockdown implementation. We find that Colombia's lockdown is associated with an increase in forest fires compared to three different counterfactuals, constructed to simulate the expected number of fires in the absence of the lockdown. To varying degrees across Colombia's regions, the presence of armed groups is correlated with this fire upsurge. Mechanisms through which the lockdown might influence fire rates are discussed, including the mobilisation of armed groups and the reduction in the monitoring capacity of state and conservation organisations during the covid-19 outbreak. Given the fast-developing situation in Colombia, we conclude with some ideas for further research.

CO2, CO, hydrocarbon gases and PM2.5 emissions on dry season by deforestation fires in the Brazilian Amazonia.

The rate of deforestation in Brazil increased by 29% between 2015 and 2016, resulting in an increase of greenhouse gas emissions (GHG) of 9%. Deforestation fires in the Amazonia are the main source of GHG in Brazil. In this work, amounts of CO2, CO, main hydrocarbon gases and PM2.5 emitted during deforestation fires, under real conditions directly in Brazilian Amazonia, were determined. A brief discussion of the relationship between the annual emission of CO2 equivalent (CO2,eq) and Paris Agreement was conducted. Experimental fires were carried out in Western Amazonia (Candeias do Jamari, Rio Branco and Cruzeiro do Sul) and results were compared with a previous fire carried out in Eastern Amazonia (Alta Floresta). The average total fresh biomass on the ground before burning and the total biomass consumption were estimated to be 591 ton ha-1 and 33%, respectively. CO2, CO, CH4, and non-methane hydrocarbon (NMHC) average emission factors, for the four sites, were 1568, 140, 8, and 3 g kg-1 of burned dry biomass, respectively. PM2.5 showed large variation among the sites (0.9-16 g kg-1). Emissions per hectare of forest were estimated as 216,696 kg of CO2, 18,979 kg of CO, 1,058 kg of CH4, and 496 kg of NMHC. The average annual emission of equivalent CO2 was estimated as 301 ±â€¯53 Mt year-1 for the Brazilian Amazonia forest. From 2013, the estimated CO2,eq showed a trend to increase in Amazon region. The present study is an alert and provides important information that can be used in the development of the public policies to control emissions and deforestation in the Brazilian Amazonia.

High-resolution inventory of mercury emissions from biomass burning in tropical continents during 2001-2017.

Mercury emissions from biomass burning contribute significantly to the atmospheric mercury budget and the interannual variation of mercury concentrations in the troposphere. This study developed a high-resolution (0.1°â€¯× 0.1°) monthly inventory of mercury emissions from biomass burning across five land types in the tropical continents (Central and South America, Africa, and South and Southeast Asia) during 2001-2017. The inventory estimates of mercury emissions from biomass burning are based on the newly released MCD64A1 Version 6 Burned Area data product, satellite and observational data of biomass density, and spatial and temporal variable combustion factors. Results from the inventory demonstrated that during 2001-2017, the average annual mercury emissions from biomass burning in tropical continents was 497 Mg and ranged from 289 Mg to 681 Mg. Forest fires were the largest contributor, accounting for 61% (300 Mg) of the total mercury emissions from biomass burning, followed by fires in woody savanna/shrubland (30%, 151 Mg), savanna/grassland (7%, 35 Mg), peatland (1%, 6 Mg), and cropland (1%, 5 Mg). However, these proportions varied between the continents; in the Americas and Asia, the largest biomass burning emissions came from forest fires, and in Africa the largest emissions were from fires woody savanna/shrubland. Between the three continents, Africa released 41% of the mercury emissions from biomass burning (202 Mg year-1), Asia released 31% (154 Mg year-1), and the Americas released 28% (141 Mg year-1). The total mercury emissions from biomass burning in these tropical continents exhibited strong interannual variations from 2001 to 2017, with peak emissions in March and August to September, and forest fires were the primary land type controlling the interannual variations.

Soil charcoal as long-term pyrogenic carbon storage in Amazonian seasonal forests.

Forest fires (paleo + modern) have caused charcoal particles to accumulate in the soil vertical profile in Amazonia. This forest compartment is a long-term carbon reservoir with an important role in global carbon balance. Estimates of stocks remain uncertain in forests that have not been altered by deforestation but that have been impacted by understory fires and selective logging. We estimated the stock of pyrogenic carbon derived from charcoal accumulated in the soil profile of seasonal forest fragments impacted by fire and selective logging in the northern portion of Brazilian Amazonia. Sixty-nine soil cores to 1-m depth were collected in 12 forest fragments of different sizes. Charcoal stocks averaged 3.45 ± 2.17 Mg ha(-1) (2.24 ± 1.41 Mg C ha(-1) ). Pyrogenic carbon was not directly related to the size of the forest fragments. This carbon is equivalent to 1.40% (0.25% to 4.04%) of the carbon stocked in aboveground live tree biomass in these fragments. The vertical distribution of pyrogenic carbon indicates an exponential model, where the 0-30 cm depth range has 60% of the total stored. The total area of Brazil's Amazonian seasonal forests and ecotones not altered by deforestation implies 65-286 Tg of pyrogenic carbon accumulated along the soil vertical profile. This is 1.2-2.3 times the total amount of residual pyrogenic carbon formed by biomass burning worldwide in 1 year. Our analysis suggests that the accumulated charcoal in the soil vertical profile in Amazonian forests is a substantial pyrogenic carbon pool that needs to be considered in global carbon models.

Indicador de vulnerabilidade socioambiental na Amazônia Ocidental. O caso do município de Porto Velho, Rondônia, Brasil / Indicator of socio-environmental vulnerability in the Western Amazon. The case of the city of Porto Velho, State of Rondônia, Brazil

O acelerado processo de urbanização na Amazônia associado às mudanças no padrão de exploração dos recursos naturais resultou em vários tipos de impactos ambientais, tal como a poluição do ar urbano produzido pelo incêndio florestal que altera a relação entre as áreas urbana e rural e reconfigura novas vulnerabilidades. O objetivo deste estudo é analisar a vulnerabilidade socioambiental em relação às queimadas e aos efeitos a saúde na área urbana do município de Porto Velho, região amazônica brasileira. Para tanto, utiliza como método a construção de um indicador síntese, que conjugou a dimensão social, de infraestrutura habitacional, exposição ambiental e de saúde. Dentre os resultados, destaca-se que 51% da população residente, 157 mil habitantes, estão sob condições de extrema e alta vulnerabilidade socioambiental. Ao final, discute-se que a análise integrada das dimensões estudadas permitiu identificar importante heterogeneidade em termos de vulnerabilidade socioambiental às queimadas no interior da área urbana de Porto Velho, apontando para a necessidade de ações integradas de diferentes setores governamentais de forma a potencializar a promoção da saúde, a sustentabilidade ecológica e a redução das iniquidades sociais em saúde.

The accelerated process of urbanization in the State of Amazônia associated with changes in the patterns of exploitation of natural resources have resulted in several types of environmental impacts, such as urban air pollution produced by forest fires which alters the relationship between urban and rural areas and establishes new vulnerabilities. The scope of this study is to analyze the socio-environmental vulnerability in relation to forest fires and health effects in the urban area of Porto Velho, located in the Brazilian Amazon region. Data was analyzed using a synthetic indicator combining income and education aspects, housing infrastructure, environmental exposure and health effects. The findings indicate that 51% of the resident population, i.e. around 157,000 inhabitants, is exposed to conditions of high and extreme environmental vulnerability. Analysis of the dimensions used to construct the synthetic indicator reveals an intense heterogeneity in terms of socio-environmental vulnerability in the urban area of the city of Porto Velho. These results highlight the need for integrated actions from different government departments in order to enhance health promotion, ecological sustainability and also reduce social inequalities in health.

Tendência da mortalidade por doenças respiratórias em idosos e as queimadas no Estado de Rondônia/Brasil: período entre 1998 e 2005 / Trend of mortality from respiratory disease in elderly and the forest fires in the state of Rondônia/Brazil: period between 1998 and 2005

As queimadas na região amazônica têm sido um problema ambiental grave. Poucos estudos relacionam os efeitos das queimadas sobre a saúde das populações expostas. Este artigo tem por objetivo estudar a tendência da mortalidade por doenças respiratórias em idosos, selecionadas no período de 1998 a 2005, no Estado de Rondônia, e correlacionar com o número de focos de queimadas. Trata-se de um estudo descritivo do tipo ecológico. Os registros de óbitos foram obtidos do Sistema de Informações de Mortalidade do SUS (SIM/SUS) e os registros de dados sobre os focos de queimadas foram obtidos através de banco de dados online disponível publicamente no Instituto Nacional de Pesquisas Espaciais. Os resultados mostraram uma tendência de crescimento nas taxas de mortalidade por doenças do aparelho respiratório (DAR) e doença pulmonar obstrutiva crônica (DPOC), entre os idosos acima de 65 anos, e também uma tendência de crescimento do número de focos de calor. Houve uma correlação positiva e significante entre número de focos de queimadas e as taxas de mortalidade por DAR e DPOC, o que explica entre 50 por cento e 80 por cento da mortalidade pelas doenças estudadas em idosos na região. Estes resultados demonstram a gravidade do problema das queimadas e o impacto sobre a saúde respiratória da população, principalmente sobre a mortalidade em idosos.

The forest fires in the Amazon region have been a serious environmental problem. Few studies relate the effects of forest fires on the health of exposed populations. This article aims to study the trend of mortality from respiratory diseases in the elderly, in the period 1998 to 2005, in the state of Rondônia and to correlate with the number of fire focuses. This is a descriptive study of the type of ecological. The death certificates were obtained from the Mortality Information System and the registers of data on the focus of fire have been obtained through online database available publicly in the National Space Research Institute. The results had shown a trend of growth in mortality rates for respiratory disease and chronic obstructive pulmonary disease (COPD) among elderly over 65 years and also a growing trend in the number of focus of heat. There was a positive and significant correlation between the number of fire focuses and mortality rates respiratory diseases and COPD, which explains around 50 percent to 80 percent of deaths by diseases in the elderly in the region studied. These results demonstrate the gravity of the problem of forest fires and the impact on respiratory health of the population, mainly on mortality in the elderly.

Incêndios na Amazônia Brasileira: estimativa da emissão de gases do efeito estufa pela queima de diferentes ecossistemas de Roraima na passagem do evento El Nino (1997/98)

The area burned, total biomass above and below-ground, charcoal formation, burning efficiency and the carbon concentration were estimated for the different natural landscapes and agricultural systems that were exposed to fire during the El Niño of 1997-98 in the state of Roraima, in the northernmost part of Brazilian Amazonia. The objective was to calculate the gross emissions of greenhouse gases released by combustion from the various biomass classes comprising each landscape type. The total area burned was 38,14440,678 km2, of which 11,394-13,928 km2 was intact primary forest, 22,583 km2 was savanna, 1,388 km2 was white sand scrub formations, and 2,780 km2 was pastures, secondary forest and agricultural plots. Total carbon affected by the fire was 42.58 x 106 tons (t), with 19.73 x 106 t being released from combustion, 22.33 x 106 t from decomposition, and 0.552 x 106 t converted to charcoal (long-term carbon storage) formed during the bums. Gross emissions of greenhouse gases emitted by combustion were 17.3 x 106 t CO2, 0.21-0.35 x 106 t CH4, 1.99-3.68 x 106 t CO, 0.001-0.003 x 106 t N2O, 0.06-0.09 x 106 t NOx and 0.25 x 106 t NMHC (non-methane hydrocarbons). The total emission in carbon equivalent to CO2 emitted by combustion, based on the global warming potentials for each gas over the 100-yr horizon used by the IPCC, was 6.1-7.0 x 106 t C.

Foi estimada a área queimada, a biomassa vegetal total acima e abaixo do solo, a formação de carvão, a eficiência de queimada e a concentração de carbono de diferentes paisagens naturais e agroecossistemas que foram atingidos pelos incêndios ocorridos durante a passagem do El Niño em 1997/98 no Estado de Roraima, extremo norte da Amazônia Brasileira. O objetivo foi o de calcular a emissão bruta de gases do efeito estufa liberados por combustão das diversas classes de biomassa que compõem cada tipo fitofisionômico atingido. A área total efetivamente queimada foi estimada entre 38.144-40.678 km2, sendo 11.394-13.928 km2 de florestas primárias (intactas, em pé) e, o restante, de savanas (22.583 km2), campinas / campinaranas (1.388 km2) e ambientes florestais já transformados como pastagens, área agrícolas e florestas secundárias (2.780 km2). O total de carbono afetado pelos incêndios foi de 42,558 milhões de toneladas, sendo que 19,73 milhões foram liberados por combustão, 22,33 milhões seguiram para a classe de decomposição e 0,52 milhões foram depositados nos sistemas na forma de carvão (estoque de longo prazo). A emissão bruta de gases do efeito estufa, em milhões de toneladas do gás, considerando apenas o emitido por combustão foi de 17,3 de CO2, 0,21-0,35 de CH4, 1,99-3,68 de CO, 0,001-0,003 de N,O, 0,06-0,09 de NOx e 0,25 de hidrocarbonetos não-metânicos (HCNM). O total de carbono equivalente a CO2 emitido por combustão, quando considerado o potencial de aquecimento global de cada gás em um horizonte de tempo de 100 anos utilizado pelo IPCC, foi de 6,1-7,0 milhões de toneladas.

Incêndios na Amazônia Brasileira: estimativa da emissão de gases do efeito estufa pela queima de diferentes ecossistemas de Roraima na passagem do evento El Nino (1997/98)

The area burned, total biomass above and below-ground, charcoal formation, burning efficiency and the carbon concentration were estimated for the different natural landscapes and agricultural systems that were exposed to fire during the El Niño of 1997-98 in the state of Roraima, in the northernmost part of Brazilian Amazonia. The objective was to calculate the gross emissions of greenhouse gases released by combustion from the various biomass classes comprising each landscape type. The total area burned was 38,14440,678 km2, of which 11,394-13,928 km2 was intact primary forest, 22,583 km2 was savanna, 1,388 km2 was white sand scrub formations, and 2,780 km2 was pastures, secondary forest and agricultural plots. Total carbon affected by the fire was 42.58 x 106 tons (t), with 19.73 x 106 t being released from combustion, 22.33 x 106 t from decomposition, and 0.552 x 106 t converted to charcoal (long-term carbon storage) formed during the bums. Gross emissions of greenhouse gases emitted by combustion were 17.3 x 106 t CO2, 0.21-0.35 x 106 t CH4, 1.99-3.68 x 106 t CO, 0.001-0.003 x 106 t N2O, 0.06-0.09 x 106 t NOx and 0.25 x 106 t NMHC (non-methane hydrocarbons). The total emission in carbon equivalent to CO2 emitted by combustion, based on the global warming potentials for each gas over the 100-yr horizon used by the IPCC, was 6.1-7.0 x 106 t C.

Foi estimada a área queimada, a biomassa vegetal total acima e abaixo do solo, a formação de carvão, a eficiência de queimada e a concentração de carbono de diferentes paisagens naturais e agroecossistemas que foram atingidos pelos incêndios ocorridos durante a passagem do El Niño em 1997/98 no Estado de Roraima, extremo norte da Amazônia Brasileira. O objetivo foi o de calcular a emissão bruta de gases do efeito estufa liberados por combustão das diversas classes de biomassa que compõem cada tipo fitofisionômico atingido. A área total efetivamente queimada foi estimada entre 38.144-40.678 km2, sendo 11.394-13.928 km2 de florestas primárias (intactas, em pé) e, o restante, de savanas (22.583 km2), campinas / campinaranas (1.388 km2) e ambientes florestais já transformados como pastagens, área agrícolas e florestas secundárias (2.780 km2). O total de carbono afetado pelos incêndios foi de 42,558 milhões de toneladas, sendo que 19,73 milhões foram liberados por combustão, 22,33 milhões seguiram para a classe de decomposição e 0,52 milhões foram depositados nos sistemas na forma de carvão (estoque de longo prazo). A emissão bruta de gases do efeito estufa, em milhões de toneladas do gás, considerando apenas o emitido por combustão foi de 17,3 de CO2, 0,21-0,35 de CH4, 1,99-3,68 de CO, 0,001-0,003 de N,O, 0,06-0,09 de NOx e 0,25 de hidrocarbonetos não-metânicos (HCNM). O total de carbono equivalente a CO2 emitido por combustão, quando considerado o potencial de aquecimento global de cada gás em um horizonte de tempo de 100 anos utilizado pelo IPCC, foi de 6,1-7,0 milhões de toneladas.